Biphilic Organophosphorus Catalysis: Regioselective Reductive Transposition of Allylic Bromides via P(III)/P(V) Redox Cycling.
Biphilic Organophosphorus Catalysis: Regioselective Reductive Transposition of Allylic Bromides via P(III)/P(V) Redox Cycling.
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DOI：
10.1021/jacs.5b01899
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发表时间：
2015-04-29
影响因子：
15
通讯作者：
Radosevich AT
中科院分区：
文献类型：
--
作者：
Reichl KD;Dunn NL;Fastuca NJ;Radosevich AT
我们报道了一个区域选择性还原转座伯烯丙基溴催化剂的二亲性有机磷（磷杂环丁烷）。光谱证据支持五配位（σ5-P）正磷烷作为关键反应中间体的形成。动力学实验和计算建模与σ5-P β-磷杂环己烷通过协同的环状过渡结构的单分子分解一致，该结构提供了所观察到的烯丙基转座并完成了新的PIII/PV氧化还原催化循环。这些结果拓宽了越来越多的剧目内的PIII/PV氧化还原对催化的反应，并建议在一个bipilic模式的有机磷催化的额外机会。
We report that a regioselective reductive transposition of primary allylic bromides is catalyzed by a biphilic organophosphorus (phosphetane) catalyst. Spectroscopic evidence supports the formation of a pentacoordinate (σ5-P) hydridophosphorane as a key reactive intermediate. Kinetics experiments and computational modeling are consistent with a unimolecular decomposition of the σ5-P hydridophosphorane via a concerted cyclic transition structure that delivers the observed allylic transposition and completes a novel PIII/PV redox catalytic cycle. These results broaden the growing repertoire of reactions catalyzed within the PIII/PV redox couple and suggest additional opportunities for organophosphorus catalysis in a biphilic mode.